The present invention relates to a collator for use in combination with an apparatus such as a copying machine, a printing machine and the like which discharges copies of original in succession.
Such a collator is often used in combination with an electrophotographic copying machine and successive copies of an original supplied from the machine are delivered into respective bins or compartments in a correct order. This mode of operation is referred to as the "collate mode" hereinafter. Such a collator can be roughly classified into three types depending on the manner of delivering the copies into the bins. In a first type, a number of bins are fixedly arranged and a distributor comprising a deflector and a copy feed mechanism is moved along a series of bins. In a second type, a series of bins are moved with respect to a copy supply position fixedly arranged in the collator. In a third type, a series of bins are fixedly arranged and at an inlet of each bin is arranged a claw like deflector. This third type of collator can be further classified into two groups. In a first group, each deflector is driven by a respective solenoid, and in a second group, each deflector is successively driven by an actuating member movable along the series of bins.
The first type of collator is of simple construction and can be easily produced. In the second type of collator, since the heavy bins must be driven, the collator can not be combined with a high speed copying machine, and requires a large space. In the first group of the third type collator, since the deflectors can be driven separately from each other, the collator can be advantageously combined with a high speed copying machine. However, each deflector has to be provided with a solenoid and a copy feed mechanism and thus, the construction is liable to be complicated and expensive. In addition control of the various parts is liable to be complex. In the second group of the third type of collator, although it is not necessary to provide a solenoid for driving deflectors, the copy feed mechanism should be provided at respective bin positions.
In the first type of collator, the distributor is returned to an initial position after the collating operation for the last copy of a certain original has been finished, but prior to the arrival of the first copy of the next original at the collator. Hereinafter, the initial position is called the "home-position". In Japanese Utility Model Application Publication No. 47,956/78, there is disclosed such a collator, in which a number of bins are arranged vertically one above the other, and a distributor is movable from the uppermost bin to the lowermost bin so as to deliver each copy of an original into a respective bin. In this collator, the distributor is returned to the home-position upon actuation of a print start switch of on the copying machine. Further Japanese Patent Application Publication No. 8,665/76 discloses a similar collator in which a distributor is returned to the home-position after a time period J has elapsed after initial detection of a copy. The period J is defined by T&gt;J&gt;t, wherein t is a time interval between successive copies of the same original and T is a time interval between the last copy of a certain original and the first copy of the next document. These collators can be effectively used in combination with commonly available copying machines in which a single exposure of an original can form a single copy and multiple copies of the original are obtained only by means of multiple exposures of the same original; thus, there is a substantial time for removing the first original and setting the next original, and said time interval T is long.
Japanese Patent Laid-Open Publication No. 12,986/80 discloses a retention type of copying machine in which a plurality of copies of an original can be obtained from the same and single electrostatic charge image once formed by subjecting it to development and transfer repeatedly. In such a copying machine of the retention type, the exposure and scanning of the second document can be initiated before a completion of a duplicating operation for the first document and thus, the time interval T from the last copy of a document to the first copy of the next document can be materially shortened and, in an extreme case, can be made identical with the time interval between successive copies of the same document. When adapting the known collators described in the above mentioned publications Nos. 8,665/75 and 47,956/78 to the retention type copying machine, it is necessary to return the distributor to the home-position during the short time interval T. However, this is very difficult. In an extreme case, if a large number of copies are to be formed, the first copy of the second document might arrive at the first bin corresponding to the home-position before the last copy of the first document has been completely delivered to the bin. In such a case, the above mentioned collators could never be used.
In order to solve the above problem, it has been further proposed to drive the distributor in a reciprocating manner. Then, however, the controlling of the distributor is liable to be difficult. Further this collator could not be used where the number of copies for successive originals are different from each other.
Various collators which could be combined with the copying machine of retention type have been proposed. For instance in one proposed collator, a number of bins are arranged vertically and successive copies are fed along the bins downward and are delivered into the bins from the lowermost bin. That is to say, the copy feed direction is made opposite to the collating direction. In such a collator, the distributor is returned to the lowermost bin at the home-position after the last copy of a document has been completely delivered into a bin, and thus, if the returning speed of the distributor is made at least equal to the copy feeding speed, the first copy of the next document can be correctly delivered into the lowermost bin. However, in such a collator, since the home-position is set at the lowermost bin and the copies are successively collated toward the upper bins, it is very inconvenient for the operator to take the collated copies out of the bins, especially when the number of copies to be formed for respective originals is relatively small. In order to avoid such a drawback, it has also been proposed to feed the copies in a direction from the lowermost bin to the uppermost bin so that the copies are successively delivered into the bins from the uppermost one. In such a collator, the operator can easily take out the collated copies, because the home-position is set at the uppermost bin and copies are successively delivered downward from the uppermost bin. However, usually the copying machine has its copy outlet at a relatively high position and thus, the collator should be provided with a copy feed mechanism for feeding the copy supplied from the copying machine to the lowermost bin. Therefore, the copy feed mechanism is liable to be large in size and complicated in construction. Further, since the copy has to travel a very long and complicated path, there might occur paper jamming.
Some collators have another function referred to as "job separation mode" or "job mode", in which all copies of respective originals are delivered into each of successive bins. In this job mode of operation, it is important that the distributor be advanced by one bin pitch. That is to say, after the last copy of a document has been completely delivered into a bin, the distributor should be advanced into next bin.
It is convenient to provide a copy detecting member at the inlet of the collator. In this way, the distributor advance timing can be set by means a copy detection signal supplied from the detecting means. However, since distances from the copy detecting means to respective bins are different from each other, it is impossible to set fixedly the distributor advance timings. This difficulty can be removed by providing a number of timers having different set times each corresponding to respective bins. However, such a solution is not preferable, because the number of timers is large and circuits related thereto are also complicated.